Method and nozzle for mixing and spraying fluids

ABSTRACT

The invention relates to a method for mixing at least two fluids using an externally mixing nozzle for medical purposes, which has at least two outlet channels ( 10, 20 ) and at least two inlet openings ( 13, 23 ) with different or identical cross-sections, wherein two fluids with different volumetric flows and/or different viscosity are sprayed, and wherein the ratio of the cross-sections of the inlet channels ( 13, 23 ) and/or the outlet channels ( 10, 20 ) corresponds to the ratio of the volumetric flows so that the fluids flow with substantially identical flow speeds through the outlet channels ( 10, 20 ) and/or the inlet openings ( 13, 23 ). The invention furthermore relates to an externally mixing nozzle, a medical instrument and a medical device for spraying substances, in particular biological material.

RELATED APPLICATION(S)

This application claims the benefit of European Patent Application No.EP 14155410.5 filed Feb. 17, 2014, the contents of which areincorporated herein by reference as if fully rewritten herein.

TECHNICAL FIELD

The invention relates to a method for mixing at least two fluids bymeans of an externally mixing nozzle for medical purposes. The inventionfurthermore relates to an externally mixing nozzle for the supply ofsubstances, in particular biological material as well as a medicalinstrument and a medical device with such a nozzle.

BACKGROUND

Nozzles for mixing fluids are known, for example, from U.S. Pat. No.5,368,563 A. In the case of the known nozzle, two vortex chambers areprovided into which in each case an outlet channel discharges.Rotational movement of two different fluids is brought about via thevortex chambers before the fluids leave the nozzle via the outletchannels. Due to the vortex applied in advance to the fluids, a rotatingspray jet is produced. Here, the two outlet openings of the known nozzleare arranged spaced apart from one another in such a manner that the tworotating fluid cones overlap so that a mixing of the two fluids takesplace outside the nozzle.

As a result of the disclosed features of the known nozzle, a uniformmixing of fluids which have a different viscosity and/or are suppliedwith different volumetric flows cannot be achieved with the desiredquality or is not possible in the first place. A further disadvantage ofthe known nozzle lies in the fact that the fluids in the vortex chambersare exposed to high stresses which is undesirable in the case of thesupply of biological material, for example, cells.

SUMMARY

The object of the invention lies in indicating a method for mixing atleast two fluids by means of an externally mixing nozzle for medicalpurposes which enables a uniform mixing of fluids. The object of theinvention further lies in indicating an externally mixing nozzle whichallows a uniform mixing of fluids and in particular enables a gentlemixing in of a biological material. The object of the invention finallylies in indicating a medical instrument and a medical device with suchan externally mixing nozzle.

By one approach, mixing at least two fluids is accomplished by means ofan externally mixing nozzle for medical purposes, which nozzle has atleast two outlet channels, out of which the fluids can exit out of thenozzle, and at least two inlet openings, through which the fluids inchambers, in particular mixing or vortex chambers, can enter. So thatthe fluids are mixed outside the nozzle, it may be expedient if at leastone of the fluids to be mixed exits in a conical jet out of the nozzle.

The at least two outlet channels and/or the at least two inlet openingscan have different or identical cross-sections. In particular, thecross-sections of the inlet openings can be different to one another oridentical. The cross-sections of the outlet channels can likewise bedifferent to one another or identical. It is also possible that thecross-section of an outlet channel differs from a cross-section of aninlet opening which is assigned to this outlet channel or thesecross-sections are identical. The diameters of the chambers canfurthermore be of a different size. In the case of the method accordingto the invention, a first fluid is conducted via a first supply channellaterally, in particular tangentially, into a first chamber which isfluid-connected to a first outlet channel. A second fluid is conductedvia a second supply channel laterally, in particular tangentially, intoa second chamber which is fluid-connected to a second outlet channel.The first fluid flows out via the first outlet channel and the secondfluid flows out via the second outlet channel so that overlapping fluidcones are formed. The degree of overlapping of the fluid cones can beformed as a function of the intended application. It is thus possiblethat the overlapping region of both fluid cones is formed from equalproportions of the two fluid cones. It is, however, also possible thatthe overlapping region is largely only formed by one fluid cone. Thefluid cones are determined by the features of the nozzle used in thecase of the method as well as the supplied fluids. The first fluid andthe second fluid can have a different viscosity and be supplied withdifferent volumetric flows, i.e. in a specific volumetric flow ratio.Moreover, the ratio of the cross-sections of the inlet openings and/orthe outlet channels corresponds to the ratio of the volumetric flows.For example, the first fluid and the second fluid can flow withsubstantially identical flow speeds through the outlet channels and/orthe inlet openings. In addition, in particular applications, thechambers can have different diameters. As a result of a correspondinglyformed nozzle, it can be ensured that the formation of fluid cones witha sufficiently large opening angle comes about despite differentvolumetric flows of the first fluid and of the second fluid. This canresult in fluid cone regions which are of approximately equal size andwhich overlap.

It is achieved with the method according to the invention that a uniformmixing of the different fluids is produced in the overlapping fluidcones. Since the flow speeds of the two fluids are adjusted to oneanother despite their different viscosity or volumetric flows, a goodand constant mixing of the fluids is achieved. In this case, the mixingis carried out outside the nozzle so that the risk of nozzle blocking isavoided. The fluids are preferably guided entirely separately from oneanother within the nozzle. In concrete terms, the cross-linking reactionor mixing of the fluids can be carried out exclusively outside thenozzle.

The nozzle used for the method according to the invention is preferablyspecially adapted to the properties of two selected fluids. Acorrespondingly adapted nozzle can thus be provided for each desiredfluid combination. The nozzles differ, for example, by thecross-sections of the outlet channels and/or the inlet openings into thechambers, and/or the chamber diameters. As a result of these geometricvariables, it is possible to selectively set the flow speeds forpredetermined fluids. The externally mixing nozzle can have both twooutlet channels with different cross-sections and also two inletopenings with different cross-sections and/or different chamberdiameters. It is also possible that the cross-sections of the outletchannels and/or the inlet openings into the chambers are identical. Theadjustment of the flow speeds can then be carried out, for example, viaa control unit which influences the fluid pressure and/or the volumetricflows of the fluids. In other words, in one preferred configuration ofthe method according to the invention, it is provided that the supply ofthe first fluid to the first chamber and/or the supply of the secondfluid to the second chamber is controlled.

In this context, reference is made to the fact that the diameter of thechamber relates to the dimension of the chamber in a plane perpendicularto the central axis of the chamber. In the case of the invention, thechamber can in particular take on the function of exerting a vortex onthe fluids flowing in via the inlet openings. To this end, the chamberpreferably has a round, in particular circular cross-section. Thediameter of the round chamber cross-section is referred to as thechamber diameter in the context of the present application.

In a further configuration of the method according to the invention, athird fluid can be conducted through a third supply channel into thesecond chamber and mixed with the second fluid. The third fluid cantherefore already be mixed with the second fluid prior to exiting out ofthe outlet opening. It is preferably provided that the second fluid andthe third fluid do not enter into any or only enter into a minorcross-linking reaction with one another. However, the first fluid canhave a cross-linking function so that cross-linking is carried out bymixing the first fluid with the mixture of the second and third fluidoutside the nozzle. Cross-linking of all the fluids is preferablycarried outside the nozzle, for example, firstly by adding the firstfluid to the mixture of the second and third fluid.

In order to reduce the stress to which the fluids are exposed, forexample, to reduce shear forces on entry of the third fluid into thesecond chamber, it can advantageously be provided that the third fluidflows in coaxially into the second chamber. In particular, the thirdfluid can flow in coaxially with respect to the second chamber into thesecond chamber, wherein the second chamber is connected coaxially to thesecond outlet channel. As a result, the third fluid can flow through thesecond chamber coaxially with respect to the second outlet channel. Itis thus largely avoided that the third fluid in the second chamber isexposed to a vortex and/or increased pressure, which would result inincreased stress, in particular shear forces or pressure. The influenceof shear forces and/or pressure on the third fluid is minimised so thata particularly gentle supply or mixing in of the third fluid is carriedout. The third fluid can contain, for example, a biological material, inparticular cells which have a high sensitivity in terms of stress. Thebiological material is protected by the coaxial supply of the thirdfluid.

In one alternative variant of the method according to the invention, athird fluid can be conducted via a third outlet channel into theoverlapping fluid cones of the first fluid and of the second fluid. Inthis variant, the third outlet channel is preferably positioned betweenthe first outlet channel and the second outlet channel so that the thirdfluid is conducted into the mixing or overlapping zone of the fluidcones of the first fluid and of the second fluid. In this manner, thethird fluid is brought into connection with the first fluid and thesecond fluid outside the nozzle so that mixing of all three fluids iscarried out entirely outside the nozzle. This avoids a blocking ofindividual outlet channels or other components of the nozzle. Thecombining of the fluids outside the nozzle furthermore brings aboutparticularly gentle mixing of these fluids.

A further alternative embodiment of the method according to theinvention provides that the third fluid is introduced directly, inparticular laterally, into the second outlet channel. The third fluid issucked in by the flow of the second fluid in the second outlet channel(Venturi principle) and thus arrives at the second outlet channelsubstantially without compressive stress, wherein at least partially amixing of the third fluid with the second fluid takes place in theoutlet channel. The third fluid is therefore mixed in with the secondfluid immediately before exiting from the nozzle, as a result of whichthe risk of nozzle blocking is reduced. At the same time, a desiredmixing of the third fluid with the second fluid is achieved.

In a further aspect, an externally mixing nozzle for the supply ofsubstances, in particular biological material, includes a first outletchannel and a second outlet channel. The first outlet channel and thesecond outlet channel are arranged spaced apart from one another so thatfluid cones exiting from the first and second outlet channels for mixingof fluids at least partially overlap. The first outlet channel isfluid-connected to a first chamber. The second outlet channel isfluid-connected to a second chamber. Moreover, a first supply channeldischarges laterally, in particular tangentially, into the firstchamber. A second supply channel discharges laterally, in particulartangentially, into the second chamber. According to the invention, atleast one third supply channel is provided which discharges coaxiallyinto the second chamber or directly into the second outlet channel or athird outlet channel.

The nozzle according to aspects of the invention enables the supply andmixing of at least three fluids, wherein the mixing of at least twofluids is carried out entirely outside the nozzle. A sticking orblocking of the nozzle is thus efficiently avoided.

The third supply channel can discharge in particular laterally into thesecond outlet channel. In other words, the third fluid guided in thethird supply channel can be mixed in perpendicular to the flow directionof the second fluid which is guided in the second outlet channel. Thistype of mixing in is particularly effective and simultaneously gentlefor substances, in particular biological material which may potentiallybe contained in the third fluid.

In one preferred variant of the nozzle according to the invention, thethird outlet channel is arranged between the first and the second outletchannel so that a fluid exiting from the third outlet channel, inparticular the third fluid, is conducted into the overlapping fluidcones. In this variant, the mixing of the at least three fluids iscarried out entirely outside the nozzle, which reliably avoids nozzleblocking. As a result of the central arrangement of the third outletchannel between the first and the second outlet channel, the stress onthe third fluid exiting from the third outlet channel e.g. as a resultof shear forces is reduced.

It can also be provided that the third supply channel is arrangedcoaxially with respect to the second outlet channel. The third fluidguided in the third supply channel thus arrives coaxially or centrallyinto the second chamber and can be mixed gently there with a secondfluid which flows via the second supply channel into the second chamber.As a result of the lateral discharge of the second supply channel, avortex arises in the second chamber, which vortex leads to turbulence sothat the third fluid, which flows in via the coaxially arranged thirdsupply channel, is well mixed with the second fluid. The coaxialarrangement of the third supply channel simultaneously brings aboutprotection of the third fluid, in particular in terms of occurringstress, in particular shear forces and/or pressure.

In order to achieve an adjustment of the flow speeds of the fluidsexiting from the outlet channels and thus an equalisation of the spraycones in terms of the speed components (axial, radial) for optimumhomogeneous distribution of the fluids and as large as possibleoverlapping of the spray cones, it can preferably be provided that thefirst chamber and the second chamber are connected in each case to thefirst or second supply channel via an inlet opening, wherein the inletopening of the first and the inlet opening of the second chamber havedifferent cross-sectional surfaces. The cross-sectional surfaces of theinlet openings of the first chamber or the second chamber can differ interms of their geometric form and/or their size. The cross-sectionalsurfaces are preferably of a different size, wherein the size differencebetween the cross-sectional surfaces is adapted such that the flowspeeds of the fluids flowing into the chamber are equalised.

In still another aspect, at least the first outlet channel and thesecond outlet channel, in particular all the outlet channels, havelongitudinal axes aligned parallel or at an angle to one another. Aparallel alignment of the longitudinal axes of the outlet channelsfacilitates the manufacture of the nozzle according to the invention. Anenlargement of the overlapping region of the fluid cones is achieved byan angular alignment of the longitudinal axes of the outlet channels.This supports the mixing of the fluids and thus improves the mixingfunction of the nozzle.

It can furthermore be provided in the case of one preferred exemplaryembodiment of the nozzle according to the invention that the secondoutlet channel has a bottleneck. The third supply channel can dischargeinto the second outlet channel in particular in the region of thebottleneck. The third supply channel preferably discharges laterally inthe region of the bottleneck into the second outlet channel. Thebottleneck can substantially form a tapering so that the outlet channelitself is formed in the manner of a Venturi nozzle. The outlet channelthus has different or varying cross-sectional diameters, wherein thecross-section of the outlet channel is preferably circular. Reference ismade to the fact that not only the second outlet channel, rather alsothe first outlet channel and/or the third outlet channel can be formedin the manner of a Venturi nozzle, i.e. can substantially have abottleneck. The bottleneck forms the smallest cross-sectional diameterof the respective outlet channel. In the case of the comparison of thecross-sectional dimensions of the inlet openings and the outletchannels, the smallest cross-sectional diameter in the region of thebottleneck is called on in terms of the outlet channels which are formedin the manner of a Venturi nozzle. The smallest cross-sectional diametercan be determined, for example, with the help of a measuring cylinderwhich is guided through the outlet channel. The diameter of the maximumlargest measuring cylinder which can be guided through the outletchannel corresponds to the cross-sectional diameter of the outletchannel at the bottleneck or at the smallest cross-sectional diameter.

The flow speed of the fluid flowing through the outlet channel is at itshighest in the region of the bottleneck so that, in accordance with theVenturi principle, a vacuum is generated in the supply channel whichdischarges in the region of the bottleneck into the outlet channel. Inthis manner, the fluid introduced laterally via the supply channel intothe outlet channel can be drawn in with the help of the fluid flowing inthe outlet channel, as a result of which pressure stresses on theincoming fluid are avoided.

A subordinate aspect of the invention relates to a medical instrumentwith a previously described externally mixing nozzle, wherein theinstrument can be connected to a medical device with an open-loop orclosed-loop control unit for setting the fluid supply.

Moreover, a medical device which is connected to a previously describedexternally mixing nozzle and/or such an instrument is described in thecontext of the invention, wherein the medical device has an open-loopand/or closed-loop control unit. The open-loop and/or closed-loopcontrol unit is configured for setting the fluid supply so that, in thecase of different volumetric flows and/or different viscosity of thefluids, these flow with substantially identical flow speeds through theoutlet channels and/or the inlet openings.

Moreover, a medical device, which is connected to an externally mixingnozzle and/or a previously described instrument, can have an open-loopor closed-loop control unit which is configured for setting the fluidsupply in such a manner that the different fluids can be suppliedindependently of one another, in any desired sequence, for example, atintervals. It is furthermore possible that a medical device has anopen-loop or closed-loop control unit which is adapted for setting thefluid supply in such a manner that the flow speeds of the fluids withdifferent volumetric flows and/or different viscosity are equalised toone another and the different fluids can be supplied independently ofone another in any desired sequence. As a result, it can be achievedthat, for example, the first fluid exits from the first outlet channelout of the nozzle, is sprayed onto a target object, at a time intervalfrom this the second fluid exits from the second outlet channel out ofthe nozzle and the mixing or cross-linking of the two fluids is firstcarried out on the target object, for example, a tissue, in particular abiological tissue.

The invention will be explained in greater detail below on the basis ofexemplary embodiments with reference to the enclosed schematic drawings.In these drawings:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: shows a cross-sectional view through an externally mixing nozzleaccording to the invention according to a preferred exemplaryembodiment, wherein the third supply channel discharges coaxially intothe second chamber;

FIG. 2: shows a cross-sectional view of an externally mixing nozzleaccording to the invention according to a further preferred exemplaryembodiment, wherein the third supply channel discharges in a thirdoutlet channel;

FIG. 3: shows a cross-sectional view of an externally mixing nozzleaccording to the invention according to a further preferred exemplaryembodiment, wherein the third supply channel discharges laterally intothe second outlet channel;

FIG. 3a : shows, in an enlarged representation, a preferredconfiguration of an outlet channel of an externally mixing nozzleaccording to the invention according to FIG. 3;

FIG. 4: shows a perspective view of an advantageous channel system of anexternally mixing nozzle according to the invention in a one-piecedesign; and

FIG. 5: shows a time diagram with an exemplary pulse sequence foractuation of the medical device in interval operation.

DETAILED DESCRIPTION

FIG. 1 shows in cross-section an externally mixing nozzle with twodifferent channel systems 5. The nozzle has two outlet channels 10, 20.Outlet channels 10, 20 terminate in an end surface 40 which delimits thenozzle. Both outlet channels 10, 20 form a first outlet channel 10 and asecond outlet channel 20. The first outlet channel 10 and the secondoutlet channel 20 are arranged spaced apart from one another. In thecase of the exemplary embodiment shown, it is clearly visible thatoutlet channels 10, 20 have different cross-sections, in particularcross-sectional diameters. Outlet channels 10, 20 are preferably formedin a circular cylinder form, wherein second outlet channel 20 has alarger cross-sectional diameter than first outlet channel 10.

First outlet channel 10 connects end surface 40 to a chamber 12 which isformed in particular as vortex chamber 12 a. Vortex chamber 12 a bringsabout turbulence of the supplied first fluid so that a conical fluid jetis generated when the fluid exits via first outlet channel 10. Fluidcone 14 of the first fluid is represented by dashed lines in thefigures.

In order to bring about a rotational movement of the first fluid invortex chamber 12 a, a first supply channel 11 discharges laterally intovortex chamber 12 a. In particular, first supply channel 11 candischarge tangentially into first vortex chamber 12 a. In other words,first supply channel 11 can have an internal wall which seamlessly orcontinuously or without a shoulder forms a transition to an internalwall of first vortex chamber 12 a.

First supply channel 11 runs substantially perpendicular to end surface40 through the nozzle and has an angled end portion 11 a which runssubstantially parallel to end surface 40 through the nozzle anddischarges into first chamber 12, in particular first vortex chamber 12a. First supply channel 11 has a first inlet opening 13 in the dischargeregion between first supply channel 11, in particular its end portion 11a, and first vortex chamber 12 a. First inlet opening 13 has a heightwhich is smaller than the height of vortex chamber 12 a. Thecross-section of first inlet opening 13 can be selected as a function ofthe viscosity or of the volumetric flow of the supplied first fluid. Forexample, first inlet opening 13 can have a height which corresponds tothe height of vortex chamber 12 a.

Second outlet channel 20 connects end surface 40 to a second chamber 22which is formed in the case of the exemplary embodiment according toFIG. 1 as mixing chamber 22 b. In a similar manner to first chamber 12,a second supply channel 21 discharges into second chamber 22. Secondsupply channel 21 runs substantially parallel to first supply channel11, i.e. perpendicular to end surface 40, and has an angled end portion21 a which discharges into mixing chamber 22 b. Angled end portion 21 aof second supply channel 21 discharges in particular via a second inletopening 23 into second chamber 22 or mixing chamber 22 b. In theexemplary embodiments represented here according to FIGS. 1 and 2,second inlet opening 23 has a height which corresponds to the height ofmixing chamber 22 b or generally second chamber 22. A differentdimensioning, in particular in terms of the cross-sectional surface, ofsecond inlet opening 23 is possible and is selected by the personskilled in the art as a function of the volumetric flow and theviscosity of the supplied second fluid.

In the case of the exemplary embodiment according to FIG. 1, it isapparent that second inlet opening 23 has a larger cross-section thanfirst inlet opening 13. It is assumed here that only the heights of thetwo inlet openings differ. The other parameters which determine thecross-sectional surface of the two inlet openings are identical. Inprinciple, the ratio between inlet openings 13, 23 can be selected to bedifferent or identical in order to set the flow speed of the fluids whenexiting out of outlet channels 10, 20 and/or when passing through inletopenings 13, 23, in particular equalise them. Not only the height ofinlet openings 13, 23, rather also the width of inlet openings 13, 23,i.e. the respective cross-sectional surface, can be varied here. Ingeneral, inlet openings 13, 23 can differ from one another both in termsof their geometric form and in terms of their dimensions.

The nozzle furthermore has a third supply channel 31 which extendssubstantially parallel to first and second supply channel 11, 21, i.e.perpendicular to end surface 40. Third supply channel 31 serves tosupply a third fluid. Third supply channel 31 discharges in the case ofthe exemplary embodiment according to FIG. 1 directly into secondchamber 22 or mixing chamber 22 b. Second chamber 22 forms a mixingchamber since both the second fluid and also the third fluid areconducted into second chamber 22 and mixed therein. Third supply channel31 preferably discharges coaxially with respect second chamber 22 intosecond chamber 22. In particular, in the case of the exemplaryembodiment according to FIG. 1, third supply channel 31, second chamber22 or mixing chamber 22 b and second outlet channel 20 are arrangedcoaxially with respect to one another. It is achieved as a result thatthe third fluid is guided substantially without deflection through thenozzle and leaves the nozzle via second outlet channel 20. A mixing ofthe third fluid with the second fluid simultaneously takes place inmixing chamber 22 b since vortexing of the second fluid in mixingchamber 22 is brought about. As a result, it is achieved that secondsupply channel 21 discharges laterally into mixing chamber 22 b. Inparticular, second supply channel 21 discharges tangentially into mixingchamber 22 b. In an analogous manner to first supply channel 11, secondsupply channel 21 also has an internal surface which forms a flush, i.e.shoulder-free, transition to an internal surface of mixing chamber 22 b.

The fluid mixture generated in mixing chamber 22 b of the second fluidand the third fluid exits out of second outlet channel 20 as secondfluid cone 24.

In general, first chamber 12 and second chamber 22 have the function ofbringing about vortexing of the fluid to be sprayed, from which therearises a conical spray jet when the fluids exit out of outlet channels10, 20. In this manner, two fluid cones 14, 24 are produced which areformed directly after end surface 40. Outlet channels 10, 20 arepreferably arranged spaced apart from one another in such a manner thatfluid cones 14, 24 overlap and form an overlapping region 34, whereinoverlapping region 34 is arranged spaced apart from end surface 40. Themixing of the fluids from fluid cones 14, 24 is carried out inoverlapping region 34. As a result of overlapping region 34 arranged ata distance from end surface 40 of the nozzle, it is ensured that fluids,which are mixed in this overlapping region 34, do not block the nozzle,in particular outlet channels 10 and 20 and vortex or mixing chambers12, 22.

In order to improve the mixing of the fluids outside the nozzle, it canbe provided that outlet channels 10, 20, in particular first outletchannel 10 and second outlet channel 20, are arranged at an angle to oneanother. The longitudinal axes of first outlet channel 10 and of secondoutlet channel 20 can therefore converge with one another, wherein thepoint of intersection of the longitudinal axes is arranged outside thenozzle. An enlarged overlapping region 34 is produced from this. In thecase of the represented exemplary embodiments, outlet channels 10, 20are aligned parallel to one another, which has advantages in themanufacture of the nozzle.

FIG. 2 shows a further exemplary embodiment of the nozzle according tothe invention with three different channel systems 5, wherein the fluidguide for the first fluid (represented on the left in FIG. 2) is formedto be substantially identical to the nozzle according to FIG. 1. Inother words, the nozzle according to FIG. 2 has a first outlet channel10 which is aligned coaxially with respect to a first chamber 12, inparticular a vortex chamber 12 a. First outlet channel 10 connects firstchamber 12 to an end surface 40 of the nozzle. A first supply channel11, which has an end portion 11 a, discharges laterally into firstchamber 12 or first vortex chamber 12 a. End portion 11 a comprises afirst inlet opening 13 in the transition region to first vortex chamber12 a. As in the case of the exemplary embodiment according to FIG. 1, arotational movement of the first fluid in first vortex chamber 12 a isbrought about in order to generate a fluid cone 14 when the first fluidexits out of first outlet channel 10.

The second fluid is also guided via a fluid guide to end surface 40which substantially corresponds to the fluid guide according to FIG. 1.In the case of the nozzle according to FIG. 2, a second outlet channel20 is provided which is arranged coaxially with respect to a secondchamber 22 and second chamber 22 is fluid-connected to end surface 40. Asecond supply channel 21 discharges into second chamber 22 via an angledend portion 21 a and a second inlet opening 23. Second supply channel 21discharges laterally, in particular tangentially, into second chamber22. In contrast to the exemplary embodiment according to FIG. 1, secondchamber 22 in the case of the exemplary embodiment according to FIG. 2is formed as second vortex chamber 22 a. No fluid mixing takes place insecond vortex chamber 22 a. Chambers 12, 22 can have different oridentical diameters. Only rotational movement of the second fluid isbrought about in second vortex chamber 22 a in order to generate a fluidcone 24 when the second fluid exits out of second outlet channel 20.

In the case of the exemplary embodiment according to FIG. 2, it is alsoapparent that first outlet channel 10 and second outlet channel 20 havedifferent cross-sections. In any case, first inlet opening 13 and secondinlet opening 23 have different cross-sections. This is, as explainedabove, variable in order to match the volumetric flows or the viscosityof the different fluids in particular of the first fluid and of thesecond fluid. For example, by setting a corresponding ratio between thecross-sections of outlet channels 10, 20 and the cross-sections of inletopenings 13, 23, optimised flow speeds, in one particular application,identical flow speeds, are set during entry of the first fluid and ofthe second fluid into vortex chamber 12 a, 22 a and/or during exiting ofthe first fluid and of the second fluid out of outlet channels 10, 20.An optimised flow speed of the first fluid and of the second fluidensures an optimum overlapping region in the case of minimal (as low aspossible) mechanical stress of the materials to be applied.

In the case of the exemplary embodiment according to FIG. 2, a thirdsupply channel 31 is also provided which extends parallel to firstsupply channel 11 and second supply channel 21. Third supply channel 31discharges directly into a third outlet channel 30 which is arrangedbetween first outlet channel 10 and second outlet channel 20. Thirdsupply channel 31 and third outlet channel 30 are aligned coaxially withrespect to one another so that the third fluid exits out of the nozzlewithout deflection. The third fluid preferably exits out of third outletchannel 30 as an e.g. low-turbulence jet 33 which flows directly intooverlapping region 34. The mixing of all three fluids is thus firstcarried out in overlapping region 34, i.e. outside the nozzle. Jet 33,which exits out of outlet channel 30, can be a coherent, continuous exitof fluid or an intermittent exit of fluid in the form of drops.

A further exemplary embodiment of a nozzle is shown in FIG. 3. Forreasons of clarity, a representation of the fluid guide of channelsystem 5 for the first fluid has been omitted. Only fluid cone 14 of thefirst fluid is shown in FIG. 3 by dashed lines. The unrepresented partof the nozzle according to FIG. 3 substantially corresponds to thecorresponding part in FIGS. 1 and 2. In other words, the nozzle has afirst outlet channel 10 which connects first chamber 12, in particularfirst vortex chamber 12 a, to end surface 40. First supply channel 11discharges laterally into vortex chamber 12 a via first inlet opening13.

The nozzle according to FIG. 3 furthermore has a further channel system5 with a second outlet channel 20 which terminates at end surface 40.Second outlet channel 20 originates from a second chamber 22 which isconfigured as a second vortex chamber 22 a. Second vortex chamber 22 ais arranged coaxially with respect to second outlet channel 20. A secondsupply channel 21 discharges laterally into second vortex chamber 22 avia a second end portion 21 a which forms a transition to second vortexchamber 22 a in the region of a second inlet opening 23. Second supplychannel 21 preferably discharges tangentially into second vortex chamber22 a. Apart from angled end portion 21 a, second supply channel 21 runsperpendicular to end surface 40.

A third supply channel 41, which is connected via an angled end portion41 a laterally to second outlet channel 20, also extends perpendicularto end surface 40. End portion 41 a of third supply channel 41preferably extends parallel to end surface 40 or perpendicular to secondoutlet channel 20.

In the case of the exemplary embodiment according to FIG. 3, it isapparent that second inlet opening 23 has a height which is smaller thanthe height of second vortex chamber 22 a. In general, the cross-sectionof second inlet opening 23 can be adapted to the viscosity or thevolumetric flow of the second fluid in order, when the second fluidexits out of the nozzle, to set a flow speed of the second fluid or thefluid mixture of the second and third fluid, which flow speed is adaptedto the flow speed of the first fluid flowing out of first outlet channel10 (not represented in FIG. 3). As a result of fluid cones 14, 24generated by means of vortex chambers 12 a, 22 a, an overlapping region34 is produced in which the fluids are mixed with one another. In thecase of the exemplary embodiment according to FIG. 3, a first mixing ofthe second fluid with the third fluid is already carried out in secondoutlet channel 20. It also applies here as in the case of the exemplaryembodiments described above that overlapping region 34 is arrangedspaced apart from the nozzle or its end surface 40.

A further embodiment of the nozzle is represented in FIG. 3a . Theconfiguration of outlet channel 20 a and of end portion 41 a of thirdsupply channel 41 is represented in the cut-out represented in anenlarged form. In this exemplary embodiment, outlet channel 20 a is, incontrast to the exemplary embodiments described above, not embodied tobe cylindrical with a constant diameter, rather is formed in the mannerof a Venturi nozzle. This means that the cross-section of outlet channel20 a has a varying diameter between its proximal and its distal end. Inconcrete terms, it is provided that outlet channel 20 a has a bottleneck15 between chamber 22 and end surface 40. It is furthermoreadvantageously provided that end portion 41 a is arranged at an angle ofless than 90° with respect to the longitudinal axis of outlet channel 20a. The discharge point of end portion 41 a is preferably arranged at thenarrowest point, i.e. in the region of bottleneck 15, of outlet channel20 a. This arrangement facilitates the generation of a vacuum in endportion 41 a and thus a suction effect on the third fluid. Thearrangement of end portion 41 a at an angle of less than 90° alsofacilitates a gentle transfer of the third fluid into second outletchannel 20 a. For improved distribution and mixing of the second andthird fluid in second outlet channel 20 a, third supply channel 41 andend portion 41 a can be present in a multiple design e.g. in triplicate(not shown in FIG. 3a ). At least end portions 41 a can be arrangedsymmetrically around outlet channel 20.

A nozzle according to the invention can have any possible combination ofthe channel systems described above for the supply of fluids. Nozzleswith at least two channel systems 5 or, for example, with four orseveral channel systems 5 are thus possible. Irrespective of the typeand/or number of channel systems used, at least two fluids are mixed inthe case of a nozzle according to the invention in an overlapping region34 which is arranged outside the nozzle.

In a further exemplary embodiment, the nozzle can be formed from one orseveral channel systems 5 which are embodied in each case in one piece.It is also possible that the entire nozzle is formed in one piece. FIG.4 shows a one-piece embodiment of a channel system 5, wherein forreasons of clarity the representation of other channel systems 5 hasbeen omitted. Outlet channels 10, 20, 30, chambers 12, 22, inletopenings 13, 23 and supply channels 11, 21, 31 (represented by a dashedline in FIG. 4) are embodied integrally in one component. In the case ofthis embodiment of the nozzle, the fluid preferably flows throughedge-free deflections into the mixing chamber. This means that radiallyoutwardly offset supply channels 11, 21, 31 are formed to be tubular. Incontrast to the exemplary embodiments described above, in the case ofwhich supply channels 11, 21 are formed by surface portions joinedtogether, in particular their deflection regions, in the case of thenozzle embodied in one piece, these deflection regions are formed bycylindrical, edge-free line portions. This enables a gradual deflectionof the fluid to be supplied even in the case of a change in thedirection of flow of up to 90 degrees. As a result, the fluid to besupplied can be supplied in a gentle manner to chambers 12, 22. Theconfiguration of supply channels 11, 21 enables a continuous, gradualdeflection of the direction of flow of the fluids flowing through thesesupply channels 11, 13 from the proximal end of the nozzle up to entryinto chambers 12, 22. Although the direction of flow proceeding from thedistal end of supply channels 40, 50, 51 up to the mixing chamberchanges by up to 90 degrees, supply channels 11, 12 are preferablyformed infinitely variably or with continuously infinitely variablecurves. In particular, supply channels 11, 12 have on this entiresection no points which generate an abrupt deflection of the directionof flow.

Supply channels 11, 12 which are substantially infinitely variablyformed or are fitted with continuous curves are particularly suitablefor the supply of biological material, in particular cells. In the caseof the exemplary embodiment according to FIG. 4, first supply channel 11discharges via an end portion 11 a into first chamber 12 or first vortexchamber 12 a. End portion 11 a of first supply channel 11 hascontinuously curved lateral surfaces so that fluid flowing through firstsupply channel 11 is guided gently in a continuous curve to first inletopening 13. The side walls of end portion 11 a of first supply channel11 forms a substantially infinitely variable transition to the sidewalls of first chamber 12 so that a vortex motion of the fluid flowinginto first chamber 12 is brought about immediately. Such a configurationof first supply channel 11 with a curved end portion 11 a and acontinuous transfer into chamber 12 is indeed particularly suitable forthe supply of biological cells or fluids which contain biological cells.Channel system 5 according to FIG. 4 is, however, also suitable for thesupply of other materials or fluids.

The variants described above of the nozzle according to the inventioncan be coupled in each case to an open-loop or closed-loop control unitin order to set the flow speeds of the fluids on exiting out of thenozzle, in particular as a function of the individual volumetric flowsand/or the individual viscosity of the fluids. The open-loop orclosed-loop control unit is directed at setting a uniform flow speed forall the fluids. The open-loop or closed-loop control unit canfurthermore bring about a spraying of the fluids, wherein the differentfluids exit out of the nozzle independently of one another and/or in anydesired sequence. In other words, the nozzle can be actuated in such amanner that fluids exit out of outlet channels 10, 20, 30 sequentiallyor simultaneously.

FIG. 5 shows by way of example a possible series of fluid supplysequences for generating a multi-layer structure of different fluidapplication layers. It can thus, for example, be provided that a firstfluid F1 is initially applied with a high volumetric flow onto a targetobject. At a time interval to the application of first fluid F1, asecond fluid F2 with a relatively smaller volumetric flow can be sprayedvia the nozzle according to the invention. First fluid F1 and secondfluid F2 can be sprayed in each case over a period of spraying, i.e. atime interval from the start of the spray jet until stopping of thespray jet, which is identical or at least similar. As is apparent inFIG. 5, first fluid F1 is first deposited on the target object. Secondfluid F2 is subsequently applied onto first fluid F1. Finally, a thirdfluid F3 can be deposited onto the laminar structure of first fluid F1and of second fluid F2 after the termination of the fluid jet of fluidF2. Third fluid F3 can be sprayed, for example, as is apparent in thediagram according to FIG. 5, with a similar or identical volumetric flowvia the nozzle as second fluid F2. In contrast to second fluid F2, thespraying period for third fluid F3 can, however, be extended. By settingthe different volumetric flows of fluids F1, F2, F3, account can betaken of the different viscosities of fluids F1, F2, F3. In this manner,it is achieved that fluids F1, F2, F3 exit out of the nozzle with thesame flow speed despite their different viscosity. It can also beprovided that fluids F1, F2, F3 in each case exit out of differentchannel systems 5 of the nozzle so that a mixing of fluids F1, F2, F3 isfirst carried out on the target object. The laminar structure accordingto FIG. 5 is therefore substantially exemplary and at most apparent fora moment. In practice, a mixing of the individual fluids is carried outdirectly on the target object.

The nozzle described above serves to mix and spray fluids. Fluids can besupplied with identical or different volumetric flows and/or haveidentical or different viscosity. The term fluid comprises here bothliquid and gaseous substances and mixtures thereof. In particular, atwo-component adhesive can be mixed and sprayed with the nozzleaccording to the invention, wherein a gluing of the nozzle channels isavoided by the externally mixing function of the nozzle. Such atwo-component adhesive normally has a bonding agent and a hardeningagent or cross-linking agent. The hardening agent or cross-linking agentis preferably sprayed as a first fluid via first supply channel 11,first chamber 12 and first outlet channel 10. For example, thrombin canbe used as the hardening agent or cross-linking agent. The bonding agentis preferably sprayed as a second fluid via second supply channel 21,second chamber 22 and second outlet channel 20. One preferred bondingagent is, for example, fibrinogen. The bonding agent and the hardeningagent or cross-linking agent first come into contact with one another inoverlapping region 34 so that the cross-linking reaction or curing takesplace outside the nozzle. Within the nozzle, the first fluid and thesecond fluid, in particular the bonding agent and the hardening agent orcross-linking agent, are guided entirely separately from one another.

In addition, a substance which has, for example, biological material, inparticular cells can be supplied as a third fluid. In order to protectthe biological material, it is provided that the third fluid is mixed inlargely without deflection, i.e. under the influence of the lowestpossible shear forces. This can be performed on one hand as a result ofthe coaxial arrangement of third supply channel 31 to mixing chamber 22b according to FIG. 1 and on the other hand as a result of a separateoutlet channel 30 in which third supply channel 31 discharges coaxially(FIG. 2). The supply of the third fluid laterally into second outletchannel 20 according to FIG. 3 also protects biological tissue which ismixed in with the third fluid.

It applies to all the exemplary embodiments that the nozzle according tothe invention preferably has volumetric flow-adapted cross-sections ofinlet openings 13, 23 in order to equalise the different viscosityand/or the different volumetric flows of the individual fluids. It isfurthermore possible to provide a different number of inlet openings 13,23 instead of individual inlet openings of different sizes. Firstchamber 12 can thus have, for example, a larger number of inlet openings13 than second chamber 22, or vice versa. Moreover, the cross-sectionsof outlet channels 10, 20 can be selected as a function of thevolumetric flow ratio of the individual fluids in order to setsubstantially identical average flow speeds of the fluids exiting out ofthe nozzle. As a result of an inclination of the central axes of outletchannels 10, 20, overlapping region 34 can furthermore be enlarged inorder to improve the mixing of the individual fluids. An angle which isgreater than 0° and less than 180° preferably exists between the centralaxes of outlet channels 10, 20.

In the context of the application, a method for mixing at least twofluids by means of an externally mixing nozzle for medical purposes isfurthermore disclosed which has at least two outlet channels 10, 20 andat least two inlet openings 13, 23 with different or identicalcross-sections, wherein two fluids with different volumetric flowsand/or different viscosity are sprayed, and wherein the ratio of thecross-sections of inlet channels 13, 23 and/or outlet channels 10, 20corresponds to the ratio of the volumetric flows so that the fluids flowwith substantially identical average flow speeds through outlet channels10, 20 and/or inlet openings 13, 23. An externally mixing nozzle, amedical instrument and a medical device for spraying substances, inparticular biological material are furthermore described.

LIST OF REFERENCE NUMBERS

-   5 Channel system-   10 First outlet channel-   11 First supply channel-   11 a End portion of first supply channel 11-   12 First chamber-   12 a First vortex chamber-   13 First inlet opening-   14 First fluid cone-   15 Bottleneck-   20 Second outlet channel-   21 Second supply channel-   21 a End portion of second supply channel 21-   22 Second chamber-   22 a Second vortex chamber-   22 b Mixing chamber-   23 Second inlet opening-   24 Second fluid cone-   30 Third outlet channel-   31, 41 Third supply channel-   33 Spot jet-   34 Overlapping region-   40 End surface-   41 a End portion of third supply channel 41

What is claimed is:
 1. An apparatus for the supply of substances, theapparatus comprising an externally mixing nozzle comprising: a firstoutlet channel and a second outlet channel, which are arranged spacedapart from one another in such a manner that fluid cones exiting fromthe first and second outlet channels for the mixing of fluids at leastpartially overlap, wherein the first outlet channel is fluid-connectedto a first cylindrical vortex chamber, and the second outlet channel isfluid-connected to a second cylindrical vortex chamber, and a firstsupply channel is configured to discharge laterally into the firstcylindrical vortex chamber, and a second supply channel is configured todischarge laterally into the second cylindrical vortex chamber; whereinthe fluids entering the first and second cylindrical vortex chambers viathe respective first and second supply channels are directedtransversely with respect to the respective fluids exiting the first andsecond cylindrical vortex chambers via the respective first and secondoutlet channels to induce a fluid vortex within each of the first andsecond cylindrical vortex chambers, wherein at least one third supplychannel is provided which discharges a liquid containing biologicmaterial including biological cells for mixing with the fluids suppliedby the first and second supply channels, wherein the third supplychannel discharges the liquid containing biologic material directly intoa third outlet channel that is arranged between the first and secondoutlet channels such that the liquid containing biologic material isreleased into the fluid cones exiting from the first and second outletchannels, so that the liquid containing biologic material is subject tolower shear forces than the fluids supplied by the first and secondsupply channels to protect the biological cells in the liquid, andwherein the first and second cylindrical vortex chambers each have across-sectional area in a plane perpendicular to a central axis of thecorresponding cylindrical vortex chamber and the first and second supplychannels each have a cross-sectional area in a plane perpendicular to acentral axis of the corresponding supply channel, and thecross-sectional area of the first cylindrical vortex chamber is greaterthan the cross-sectional area of the first supply channel, and thecross-sectional area of the second cylindrical vortex chamber is greaterthan the cross-sectional area of second supply channel.
 2. The apparatusaccording to claim 1, wherein the first vortex chamber and the secondvortex chamber are connected in each case to the first or second supplychannel via an inlet opening, wherein the inlet opening of the firstvortex chamber and the inlet opening of the second vortex chamber havedifferent cross-sectional shapes.
 3. The apparatus according to claim 1,wherein at least the first outlet channel and the second outlet channelhave longitudinal axes oriented parallel or at an angle to one another.4. The apparatus according to claim 1, further comprising a medicalinstrument having the externally mixing nozzle, wherein the instrumentis configured to connect to a medical device with a control unit forsetting the supply of substances to the first, second, and third supplychannels.
 5. The apparatus according to claim 4, wherein the firstvortex chamber and the second vortex chamber are connected in each caseto the first or second supply channel via an inlet opening; wherein thecontrol unit is adapted for setting the supply of substances to thefirst, second, and third supply channels in such a manner that, withdifferent volumetric flows and/or different viscosity of the fluids,said fluids flow with substantially identical flow speeds through theoutlet channels and/or the inlet openings.
 6. The apparatus according toclaim 4, wherein the control unit is adapted for setting the supply ofsubstances to the first, second, and third supply channels in such amanner that the different fluids can be supplied independently of oneanother in any desired sequence.
 7. The apparatus according to claim 1,wherein the first vortex chamber and the second vortex chamber areconnected in each case to the first or second supply channel via aninlet opening; further comprising a control unit which is adapted forsetting the supply of substances to the first, second, and third supplychannels in such a manner that, with different volumetric flows and/ordifferent viscosity of the fluids, said fluids flow with substantiallyidentical flow speeds through the outlet channels and/or the inletopenings.
 8. The apparatus according to claim 7, wherein the controlunit is adapted for setting the supply of substances to the first,second, and third supply channels in such a manner that the differentfluids can be supplied independently of one another in any desiredsequence.
 9. The apparatus according to claim 1, further comprising acontrol unit which is adapted for setting the supply of substances tothe first, second, and third supply channels in such a manner that thedifferent fluids can be supplied independently of one another in anydesired sequence.
 10. A method for mixing at least two fluids, themethod comprising: using an externally mixing nozzle, which has at leasttwo outlet channels and at least two inlet openings with different oridentical cross-sections, to mix at least two fluids, by: conducting afirst fluid via a first supply channel laterally into a firstcylindrical vortex chamber which is fluid-connected to a first outletchannel, conducting a second fluid via a second supply channel laterallyinto a second cylindrical vortex chamber which is fluid-connected to asecond outlet channel which is spaced apart from the first outletchannel, such that the fluids entering the first and second cylindricalvortex chambers via the respective first and second supply channels aredirected transversely with respect to the respective fluid exiting thefirst and second cylindrical vortex chambers via the respective firstand second outlet channels to induce a fluid vortex within each of thefirst and second cylindrical vortex chambers, and wherein the first andsecond cylindrical vortex chambers each have a cross-sectional area in aplane perpendicular to a central axis of the corresponding cylindricalvortex chamber and the first and second supply channels each have across-sectional area in a plane perpendicular to a central axis of thecorresponding supply channel, and the cross-sectional area of the firstcylindrical vortex chamber is greater than the cross-sectional area ofthe first supply channel, and the cross-sectional area of the secondcylindrical vortex chamber is greater than the cross-sectional area ofsecond supply channel, flowing the first fluid out via the first outletchannel and the second fluid out via the second outlet channel in such amanner that overlapping fluid cones are formed, wherein the first fluidand the second fluid have different volumetric flows and a ratio of thecross-sections of the inlet openings and/or the outlet channelscorresponds to a ratio of the volumetric flows so that the first fluidand the second fluid flow with substantially identical average flowspeeds through the outlet channels and/or the inlet openings, andwherein at least one third supply channel is provided which discharges aliquid containing biologic material including biological cells formixing with the first and second fluids, wherein the third supplychannel discharges the liquid containing biologic material directly intoa third outlet channel that is arranged between the first and secondoutlet channels such that the liquid containing biologic material isreleased into the fluid cones exiting from the first and second outletchannels, so that the liquid containing biologic material is subject tolower shear forces than the fluids supplied by the first and secondsupply channels to protect the biological cells in the liquid.
 11. Themethod according to claim 1, further comprising controlling the supplyof the first fluid to the first vortex chamber and/or the supply of thesecond fluid to the second vortex chamber.
 12. The method according toclaim 1, further comprising conducting a liquid containing biologicmaterial including biological cells via the third outlet channel intothe overlapping fluid cones of the first fluid and of the second fluid.